As President Donald Trump made waves over the weekend with his latest tweets, another high-profile public official emerged as a lively—if less provocative—new voice on the social network.

Manhattan U.S. Attorney Preet Bharara, the prosecutor who has battled insider-trading and Albany’s top lawmakers, launched a personal Twitter account on Friday. It was a rare step for a top federal law-enforcement official, and one that prompted a flurry of chatter in legal and political circles about his motives.